G Protein-Coupled Receptors Signaling to MAPK/Erk Interactive Pathway

Pathway Description:

G protein-coupled receptors (GPCRs) are activated by a wide variety of external stimuli. Upon receptor activation, the G protein exchanges GDP for GTP, causing the dissociation of the GTP-bound α and β/γ subunits and triggering diverse signaling cascades. Receptors coupled to different heterotrimeric G protein subtypes can utilize different scaffolds to activate the small G protein/ MAPK cascade, employing at least three different classes of Tyr kinases. Src family kinases are recruited following activation of PI3Kγ by β/γ subunits. They are also recruited by receptor internalization, crossactivation of receptor Tyr kinases, or by signaling through an integrin scaffold involving Pyk2 and/or FAK. GPCRs can also employ PLCβ to mediate activation of PKC and CaMKII, which can have either stimulatory or inhibitory consequences for the downstream MAPK pathway.